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EPA funds UMD research on Great Lakes food chain

Lisa Allinger (left), research fellow at the NRRI, and Meagan Aliff, graduate research assistant, help Euan Reavie, NRRI senior research associate, assemble and prepare the equipment needed to gather a core sample from the bottom of Superior Bay in March, 2014. (file photo / News Tribune)

The U.S. Environmental Protection Agency is pumping another $2.5 million over the next five years into University of Minnesota Duluth's research on the makeup of tiny organisms at the bottom of the Great Lakes.

UMD's Natural Resources Research Institute announced the grant Wednesday as the continuation of funding from the federal government in the quest to know how the lakes' food chains have changed over the centuries and what's stressing the lakes today.

NRRI researchers have been looking at algae in the lakes during the past decade, including studying core samples that expose algae from centuries ago.

Now, the effort will expand to areas of the lakes closer to the shoreline and will include deploying robots to collect data all year, even under winter ice.

In the past 10 years, researchers lead by the NRRI's Euan Reavie have documented historical Great Lakes water quality changes going back 200 years using algae fossils in sediment as indicators of change. This has given the scientists a better understanding of the long-term impacts of nutrient overloads, invasive-species introductions and climate change — especially accelerated in the last 30-40 years — as well as positive impacts of efforts to fix problems, such as reducing phosphorus runoff.

The evidence shows vast changes over the years with "profound impacts," said Reavie, an aquatic ecologist who specializes in paleolimnology — the study of historic sediment in lakes and rivers.

"Because of the discoveries we've made so far and the incredible food web impacts, this is a natural progression for the research," Reavie said in a statement announcing the grant, "We need more thoroughly collected data to make predictions about where things are going, especially with climate change impacts."

Two submerged buoys with remote sampling devices will be stationed in each of the lakes to collect and preserve phytoplankton samples and store them until retrieved a full year later.

"The winter food web is probably pretty important, but we've never been able to get under the ice to collect samples," Reavie noted. "What species are 'winter' species? What happens before spring thaw to set up changes for the next season? Right now, we just don't know."

Areas to be studied closer to shore will be closer to the stress associated with human activities on the land, and may tell a story that more directly reflects human-Great Lakes interactions.

Scientists note that what happens at the bottom of the food chain, often at the bottom of the lake, has a big impact on fish at the top of the food chain.

"The tiny species we see from 200 years ago are completely different than what we see today," Reavie said. "They keep changing because of human activities. If you care about cold water fisheries, you should really care about what's happening at the bottom of the food web."